/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.tsfile.read.common.block.column;

import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.utils.Binary;
import org.apache.iotdb.tsfile.utils.TsPrimitiveType;
import org.openjdk.jol.info.ClassLayout;

import java.util.Arrays;

import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static org.apache.iotdb.tsfile.read.common.block.column.ColumnUtil.checkValidRegion;

public class RunLengthEncodedColumn implements Column {

    private static final int INSTANCE_SIZE =
            ClassLayout.parseClass(RunLengthEncodedColumn.class).instanceSize();

    private final Column value;
    private final int positionCount;

    public RunLengthEncodedColumn(Column value, int positionCount) {
        requireNonNull(value, "value is null");
        if (value.getPositionCount() != 1) {
            throw new IllegalArgumentException(
                    format(
                            "Expected value to contain a single position but has %s positions",
                            value.getPositionCount()));
        }

        if (value instanceof RunLengthEncodedColumn) {
            this.value = ((RunLengthEncodedColumn) value).getValue();
        } else {
            this.value = value;
        }

        if (positionCount < 0) {
            throw new IllegalArgumentException("positionCount is negative");
        }

        this.positionCount = positionCount;
    }

    public Column getValue() {
        return value;
    }

    @Override
    public TSDataType getDataType() {
        return value.getDataType();
    }

    @Override
    public ColumnEncoding getEncoding() {
        return ColumnEncoding.RLE;
    }

    @Override
    public boolean getBoolean(int position) {
        return value.getBoolean(0);
    }

    @Override
    public int getInt(int position) {
        return value.getInt(0);
    }

    @Override
    public long getLong(int position) {
        return value.getLong(0);
    }

    @Override
    public float getFloat(int position) {
        return value.getFloat(0);
    }

    @Override
    public double getDouble(int position) {
        return value.getDouble(0);
    }

    @Override
    public Binary getBinary(int position) {
        return value.getBinary(0);
    }

    @Override
    public Object getObject(int position) {
        return value.getObject(0);
    }

    @Override
    public boolean[] getBooleans() {
        boolean[] res = new boolean[positionCount];
        Arrays.fill(res, value.getBoolean(0));
        return res;
    }

    @Override
    public int[] getInts() {
        int[] res = new int[positionCount];
        Arrays.fill(res, value.getInt(0));
        return res;
    }

    @Override
    public long[] getLongs() {
        long[] res = new long[positionCount];
        Arrays.fill(res, value.getLong(0));
        return res;
    }

    @Override
    public float[] getFloats() {
        float[] res = new float[positionCount];
        Arrays.fill(res, value.getFloat(0));
        return res;
    }

    @Override
    public double[] getDoubles() {
        double[] res = new double[positionCount];
        Arrays.fill(res, value.getDouble(0));
        return res;
    }

    @Override
    public Binary[] getBinaries() {
        Binary[] res = new Binary[positionCount];
        Arrays.fill(res, value.getBinary(0));
        return res;
    }

    @Override
    public Object[] getObjects() {
        Object[] res = new Object[positionCount];
        Arrays.fill(res, value.getObject(0));
        return res;
    }

    @Override
    public TsPrimitiveType getTsPrimitiveType(int position) {
        return value.getTsPrimitiveType(0);
    }

    @Override
    public boolean mayHaveNull() {
        return value.mayHaveNull();
    }

    @Override
    public boolean isNull(int position) {
        return value.isNull(0);
    }

    @Override
    public boolean[] isNull() {
        boolean[] res = new boolean[positionCount];
        Arrays.fill(res, value.isNull(0));
        return res;
    }

    @Override
    public int getPositionCount() {
        return positionCount;
    }

    @Override
    public long getRetainedSizeInBytes() {
        return INSTANCE_SIZE + value.getRetainedSizeInBytes();
    }

    @Override
    public Column getRegion(int positionOffset, int length) {
        checkValidRegion(positionCount, positionOffset, length);
        return new RunLengthEncodedColumn(value, length);
    }

    @Override
    public Column subColumn(int fromIndex) {
        if (fromIndex > positionCount) {
            throw new IllegalArgumentException("fromIndex is not valid");
        }
        return new RunLengthEncodedColumn(value, positionCount - fromIndex);
    }

    @Override
    public void reverse() {
        // do nothing because the underlying column has only one value
    }
}
